Steam-generating apparatus for automobiles.



A. G. DAVIS, STEAM GENERATING APPARATUS FOR AUTOMOBILES.

1APPLIOYA'I'ION FILED JUNE 16, 1904. I 974,129, Patented Nov. 1, 1910.

i sums-exam 1.

A. G. DAVIS.

STEAM GENEBATINGAPPARATUS FOR AUTOMOBILES.

APPLICATION FILED JUNE 16,-1904.

0 12 MB n v 6. 0T Nu H m m a P lnvenifnf v WimeisSes 1": "cums PETERS (30., wasumcron, n. c.

UNITED STATES PATENT OFFICE.

ALBERT G. DAVIS, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Nov. 1, 1910.

Application filed June 16, 1904. Serial No. 212,782.

To all whom it may concern:

Be it known that I, ALBERT G. DAVIS, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Steam-Generating Apparatus for Automobiles, of which the following is a specification.

My invention relates to the generation of steam or other vapor, and relates more especially to those systems employing boilers having no substantial storage space for vapor and liquid. The general theory of operation underlying such systems is that the quantity of steam generated should vary in accordance with the demand. The usual manner of accomplishing this result is to regulate the quantity of liquid supplied to the boiler, which may be done either manually or automatically.

In operating a steam propelled carriage in which the system is automatically controlled, it has been my experience that the supply of steam is not equal to the demand under all conditions of load. There are times when the working pressure of the steam is inadequate and far below the demand, and at other times it is in excess. In other words, a fixed working pressure is not satisfactory for automobile work because of the wide variations in load. 7

The object of the present invention is to overcome the objection above pointed out and to provide a regulating mechanism for vapor-generating systems which can be set or adjusted to maintain a constant or substantially constant vapor pressure to meet one condition of'operation, and reset or readjusted by the operator from the vehicle seat'to maintain a different but a constant or substantially constant vapor pressure to meet a new condition of operation.

For an understanding of what I regard as novel in my system, reference is made to the following description and the claims appended thereto, taken with the accompanying drawings which illustrate one of several embodiments of which my invention is capable.

In the accompanying drawings, Figure 1 is a side elevation of an automobile with portions broken away to show parts of the steam system with which it is equipped, and Fig. 2 is a diagram of the system.

Referring more particularly to Fig. 2, 1

represents a boiler that is supplied from the tank 2 with water or other liquid by means of a foot pump 3 or a power pump 4, and in turn suppliessteam to the engine 5 under the control of the throttle 6. The pump 4 is of the variable stroke type and is operated by two co-acting motors which are connected with the pump piston in such a manner as to permit the length of stroke to vary automatically according to the pressure of the fluid in the supply pipe leading to the boiler. This enables the effective delivery of the pump to vary so that it may cooperate with the fuel supply to maintain the pressure on the boiler substantially constant within certain limits of load. One motor has a constant length of stroke and is adapted to move the pump piston in one direction only, while at the same time setting the other motor to enable it to perform the return stroke of the piston, a lost-motion connection being provided between the piston and first motor so that the stroke of the second motor may vary when the pressure in the supply pipe tends to exceed the power of the second motor.

The constant stroke motor comprises an eccentric 7 or other means which imparts a reciprocating motion, a cross-head S, and a frame 9. The frame consists of cross bars 10 and 11 and parallel side rods 12 connected to form a rigid structure. The side rods extend loosely through openings in an abutment-13 which is rigidly secured to the piston 1 1 of the pump 4, and the cross bar 11 is disposed intermediate the pump cylinder and the moving abutment 13. By this arrangement the cross-bar engages with the abutment and withdraws the piston from the pump. The piston extends freely through an opening 15 in the cross-bar so that the return stroke of the frame has no effect or is idle relatively to the piston, thus forming a lost-motion connection. The return stroke of the piston is performed by a motor whose length of stroke is capable of variation in accordance with the pressure of liquid on the piston when said pressure tends to exceed a predetermined amount, and for this purpose it must be elastic or the equivalent. Accordingly springs 16 are employed which are attached at corresponding ends to the abutment 13 of the piston and at the opposite end to an abutment 17 which is fixed relatively to the piston, but

is capable of adjustment, as will be explained hereinafter. By this arrangementthe springs are placed under a working ten sion or are set when the piston is moved by the constant stroke motor so as to return the piston. The two motors are so related that the constant stroke motor withdraws the piston from the pump cylinder and the springs return the piston, or, in other words, the motors respectively perform the suction and the discharge strokes of the pump.

The springs 16 may be set to exert a pull of any predetermined amount. This means that the pump will deliver liquid to the boiler at a pressure substantially equivalent to the pull of the springs, friction being neglected. If for any reason the pressure on the boiler or delivery pipe should tend to increase, the .springs yield to a greater or less extent, proportionately to the tendency of the pressure to increase, thereby varying the length of stroke of the piston and consequently the delivery of the pump. These variations may extend from maximum to zero, according to the operating conditions so as to cooperate with the fuel supply to maintain the pressure on the boiler substantially constant over a limited range.

During the time the piston stroke varies, the lost-motion connection is brought into play, and in order to prevent hammer blows between the abutment 13 on the piston and the cross bar 11 of the constant stroke motor, an elastic buffer or washer 18 is arranged between them which yieldingly takes up the shock.

The arrangement specified is particularly adapted to manual regulation, whereby the working pressure of the steam or other vapor may be increased or decreased to suitany given service. In order to accomplish this the tension of the springs may be adjusted so that the pump will deliver liquid at the desired pressure, and tend to maintain such pressure substantially constant. It is one of the objects of my invention to facilitate such adjustment of the apparatus for changing the working pressure, by enabling this to be done from the operators seat and while the vehicle is running. For this purpose a controller is provided which is conveniently accessible to the operator. The controller is connected with the abut ment 17 by any suitable power-multiplying mechanism whereby the operation is rendered easy. In one way of carrying out this feature, the adjustable abutment is provided with a rack 19 with which meshes a pinion 20 that is actuated by a worm 21. The worm may be mounted 011 the shaft of the controller 22, as shown in Fig. 2, or it'may be mounted on a countershaft23 which is actuated by a manually-actuated shaft or controller M, as shown in Fig. 1. Any equivalent means may be employed, for in its broad aspect my invention embraces any power-multiplying means between the controller and adjustable abutment. By imparting motion to the pinion through the worm, the rack is moved rectilinearly in one direction or the other, thereby increasing or decreasing the tension of the springs of the pump, and hence by cooperation with the fuel pump 33 increasing or decreasing the pressure of the steam supplied by the boiler.

In order to dispense with the use of the foot pump, and to assist the power pump in some cases, an accumulator 25 is connected with the liquid supply pipe. A check valve 26 is provided in the connection between the-80 supply pipe and accumulator which opens inwardly toward the latter to permit fluid to pass either directly from the pump or the boiler or from both, and automatically closes to the flow of fluid from the accumulator, thereby maintaining the pressure therein. In order to supply the boiler from the accumulator, a bypass 27 is arranged around the check valve and this is provided with a manuallycontrolled valve 28 which can be operated from the vehicle seat.

The boiler is heated by a burner 29 which may be supplied from a main fuel supply tank 30, or from an auxiliary supply tank 31, the latter, however, being employed to supply fuel in such quantity as to support a pilot flame, and may feed fuel to the burner under air pressure, a valve 32 being provided for controlling the supply of fuel therefrom.

In order to increase the pressure of fuel supplied from the main tank 30, a power pump 38 is employed which may be driven by an arrangement similar to that shown for driving the water pump. By this means the pressure in the fuel system may be automatically maintained at any desired pressure and may be readily adjusted from one operating pressure to another at will, which feature in connection with the similar means for the Water regulation affords great flexibility of control.

Considering the operation of the system, let it be assumed that the pressure of steam or other vapor best suited for a given service is 400 lbs. per square inch. To maintain this pressure the springs 16 will be set to work against 400 lbs. without yielding so as to enable the pump to deliver its maximum out-put. When the steam pressure exceeds this point the springs will yield and reduce the stroke of the pump, and hence the quantity of Water delivered to the boiler. lVhen the condition of load on the engine changes, as in ascending steep grades or traveling over heavy roads, considering the system to be an equipment for an automobile as shown. steam at a higher pressure will then be required to meet this changed condition. In order to meet this demand, the tension of the springs must be increased to the desired 130 degree so that they will give the necessary power to operate the pump at its full stroke against the higher pressure selected, and when the pressure of steam increases beyond this point the springs will yield and shorten the strokes of the pump, and thereby automatically tend to maintain the pressure constant. Should the desired pressure be 600 lbs, the springs would be adjusted to develop a pull of 600 lbs., disregarding any friction, and thereby the pump will supply suflicient water to generate steam at 600 lbs. per square inch. At pressure beyond this the stroke of the pump decreases. The pressure in the accumulator will also rise correspondingly to that in the boiler, namely 600 lbs.

As the load on the system changes it may be desirable to make the change in the effective action of the burner correspond with or even be different from the change in the water supply. Thus the capacity of the pumps of the system, and consequently that of the boiler and burner, may be varied to suit Wide ranges of working conditions. 'It will be noted that a system of this character is advantageous both on the score of economy in operation and flexibility of control.

In accordance withthe provisions of the patent statutes. I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus can be carried out by other means.

WVhat I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a steam generating system, the combination of a boiler, a burner therefor, automatic variable stroke pumps for supplying water to the boiler and fuel to the burner at constant pressures, and separate controllers for the pumps whereby the pressure of their deliveries may be varied.

2. In a steam generating system, the combination of a boiler, a burner for heating the boiler, pumps for supplying water to the boiler and liquid fuel to the burner at pressures suitable for generating steam at the pressure necessary to meet a given condition of operation of a driven device, motors for driving the pumps, and separate controllers for regulating the action of the motors to vary the pressures at which the water andfuel are delivered to the boiler and burner to thereby generate steam at other pressures suitable for different operating conditions.

3. In a steam generating system, the combination of a boiler, a burner for heating the boiler, pumps for supplying water and liquid fuel to the boiler and burner respectively, driving motors for the pumps, connections between the motors and pumps for actuating them on their suction and discharge strokes, automatic regulators forming part of the motors which are responsive to the pressure of the discharged fluids and cause the pumps to deliver fluid at a constant pressure, and devices for manually controlling the regulators by which said regulators can be adjusted during the operation of the pumps to cause them to deliver fluid at any arbitrary pressure, said pres sure being maintained by the regulators at a constant value during any given adjustment.

4. In a steam generating system, the combination of a boiler, a burner for heating the boiler, pumps for supplying water and liquid fuel to the boiler and burner respectively, means for actuating the pumps in one direction, a device for actuating them in the .opposite direction to deliver fluid at substantially constant pressure, which device also controls the effective discharge of the pumps and decreases said discharge when the pressure against which they work reaches a predetermined amount, and manually controllable means for adjusting said device during the operation of the pumps to vary the maximum pressures at which the pumps discharge. a

5. In a steam generating system for automobiles, the combination of a boiler, a burner for heating the boiler, water and fuel pumpsfor supplying the boiler and burner respectively, connections between the pumps and the boiler and burner, adjustable means for driving the pumps which of itself tends to operate the pumps to automatically sup ply fluid to said boiler and burner at sub stantially constant pressure for any given adjustment, and controller mechanism that can be operated from the vehicle seat for adjusting said means to supply said fluids at constant pressures the value of which can be varied by said adjustment.

6. In a steam generating system for automobiles, the combination of a boiler, a burner for heating the boiler, a pump for supplying fuel to the burner, a pump for supplying water to the boiler, a motor for driving the water pump comprising a device responsive to the pressure in the boiler which automatically varies the stroke of the pump and causes it to deliver water at constant pressure to the boiler to cooperate with the fuel supply to generate steam at a pressure suitable for a given operating condition, and controller mechanism that can be operated from the vehicle seat for adjusting said device to cause the pump to deliver water at another pressure suitable for a different operating condition, said pressure being maintained constant by said device.

In witness whereof I have hereunto set my hand this 14th day of June, 1904.

ALBERT G. DAVIS.

Witnesses:

BENJAMIN B. HU'LL, HELEN ORFORD. 

